I'm so glad you decided to take this approach! Planetary Annihilation just slows everyone down when a single guy plays on a toaster, and it's horrible.The update can now simulate more than one logical game steps (up to 3 currently) without rendering it, to catch up with the time-schedule. This results in laggy (but not slowed) experience for the player with slower computer, but it doesn't slow down all the other players. This also means, that the low-fps mode is no longer needed, as it is automatically solved by this system as an side-effect.
By the way, as I understand, does this mean the game will no longer slow down in SP either, and will instead lower the FPS, like most games do?